Field of the Invention
The present invention relates to a network self-construction method, in which a system manager performs network construction of network devices into multiple networks in a desired structure.
Description of Related Art
With the recent advances in Micro Electro Mechanical System (MEMS)-based sensor technologies, low-power analog and digital electronic technologies, low-power RF design technologies, and the like, research has been actively conducted to develop wireless sensor network technologies using low-cost, low-power sensors. A wireless sensor network includes an access point (AP) that controls a network operation, and a plurality of network devices that are controlled by the AP.
The following wireless networking technology is essential for an application environment in which network devices must be separated into a number of networks in the same space. First, a system manager must be able to perform network construction by separating network devices into multiple networks in a desired structure. That is, the system manager must be able to connect each network device to a specific network. Second, the system manager must support network association of additional network devices and network transfer of network devices to other networks.
For example, considering an application environment in which network devices in an office are managed by a plurality of APs, network devices of a specific section area must be associated to an AP managing the corresponding section area. When it is necessary to change the section area of some network devices after network construction, the network devices must be able to leave the existing network and make association to a new network.
ZigBee, 6LoWPAN, or the like, which is a representative low-power wireless networking technology, cannot support the above-described self-construction of multiple wireless networks. For example, in the case of ZigBee, when a plurality of APs are installed in the same place and network devices are powered on, the network devices attempt to make association to an arbitrary AP. Thus, a system manager cannot perform the multiple-network construction in a desired structure. Z-Wave can manually construct a network, in which a controller needs to manually take care of each network device for network association to the network. Thus, Z-wave is applicable only to the construction of a small-size network.